1.1 Field
Fluorescence quenchers and methods for using the same are described herein.
1.2 Introduction
Energy transfer (ET) probes are used widely in fluorescence detection of specific target molecules—including DNA, RNA and proteins. ET probes generally consist of a reporter dye labeled analyte specific reagent whose fluorescence signal is quenched by a neighboring quencher chromophore. Typically, the quencher chromophore is covalently linked to the reporter. A change in fluorescence, as a result of a change in quenching, occurs upon interaction with a target. Unfortunately, quenchers available to date tend to have low absorptivity as measured by their extinction coefficients. Often, the extinction coefficients are less than 50,000 and more typically less than 30,000, although some quenchers with higher extinction coefficients are available. A quencher with low absorbitivity will have a low quenching capacity of a reporter by Förster energy transfer. In addition, quenchers have a limited range of absorption. Generally, the range of wavelengths that can be absorbed by a quencher is only 150-200 nm wide. Accordingly, there is an ever present need to develop a wider selection of quenchers, as well as quenchers that exhibit higher emission absorbtivity and/or wider ranges of absorption.